On-vehicle closable type display apparatuses include a display apparatus attached on the ceiling of an automobile vehicle, as shown in FIG. 4. In the display apparatus, a display panel 10 is drawn and raised from the side of the ceiling, and is rotated through a suitable angle to be held at the position in service, thus enabling an occupant at a rear seat to see images on the display panel. The display panel 10 is rotated and returned to the side of the ceiling, and is housed to be held at the position out of service, thus causing the panel not to obstruct the view, and also not to be damaged on the display surface by being accidentally touched. In general, an opening and closing structure for such operation has a structure where a rotating shaft having the display panel 10 fixed thereon is rotatably supported by a bearing supporting member secured on the side of a ceiling.
Meanwhile, this type of closable display apparatus has a problem of an influence caused by the vibration of a vehicle. As an example of the measures thereagainst, there is a technology (e.g., see Patent Document 1), in which an engaging groove is provided along the outer surface of the generally central portion of a rotating shaft supporting a display panel on the sides of both the ends of the panel; moreover, a tension plate is provided, which extends vertically from a fixed base provided on the ceiling of the room of a vehicle or the like; a U-shaped pawl provided at the tip of the tension plate is engaged in the engaging groove provided along the rotating shaft; and thereby the rotating shaft axially moved by the vibration is arranged to be returned to the original position by the elastic force of the tension plate. According to the document, when the technology is applied, an axial load imposed on the rotating shaft by the vibration of the display panel existing in an opened state can be suppressed, retainers such as C rings or E rings for preventing the shaft from coming off can be prevented from being dislodged by the vibration load, and the rotating shaft can be prevented from falling out of a bearing supporting member.    Patent Document 1: JP-A-2004-203300 (FIG. 6 and FIG. 7)
In a conventional closable type display apparatus as disclosed in Patent Document 1, a rotating shaft is held against axial displacement imposed thereon by vibration with the elastic force of a tension plate, and thus the display apparatus has a limitation to such vibration having a large amplitude as causes the swing of the display panel, which may influence the image. Further, in the conventional structure, there is a problem that the number of man-hours increases in providing grooves along the rotating shaft, adding members for the tension plate, assembling the members, and adjusting the assembled members, and this can become a factor of increased cost.
In particular, when the display panel is in an opened state, the rotating shaft at the upper edge of the panel is supported by the bearing supporting member only at two points of both the ends thereof, and thus the vibration axially produced is transmitted to the bearing supporting member in cooperation with the weight (e.g., 1 kg) of the display panel hanging down, as a heavy load. As a result, there occurs a problem that the bearing supporting member is axially bent to cause the display panel to be swung, thus making the image hard to see. For example, keeping on watching the swinging images sometimes causes an occupant to get seasick. Further, when the display panel is in a closed state, there is a problem that the clearance between the display panel and the panel housing section is not maintained uniform to deteriorate the appearance of the display apparatus.
The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a closable type display apparatus capable of preventing the display panel from being swung by the vibration of a vehicle in service.